Turn off Wifi when Ethernet is connected

Hello,

Sorry for this question but i don't i've found any subject about this :
So, I've a PirateBox composed with a MR3040.

I would like to set up this functionnality on it ... if it's possible :

When i plug an ethernet cable on my pirate box, i would like to automaticaly turn off wifi (on it :)).
Because I'm ready to share all the content of my piratebox but not my whole network :)

Do you think is it possible ?

thanks in advance.

Regards,
TheCause.
PS : English is not my mother tongue.